05.00 Waves and Optics Introduction

Module 05: Waves and Optics

The big idea A wave is energy traveling through a medium (or, for light, through nothing at all) without the medium itself traveling along with it. Every lesson in this module is one specific case of that one idea, from a swinging pendulum to a rainbow to an ambulance siren changing pitch as it passes.

Before you start: what a wave actually is

The word 'wave' gets used loosely (a wave of applause, a heat wave). Physics means something narrow and specific by it, and if that narrow meaning clicks now, every lesson from here to the exam gets easier.

Not sure about the basics underneath this lesson?

Module 05 at a glance

LessonFocus
05.01 Simple Harmonic Motion Pendulum lab: what actually controls how fast a pendulum swings
05.02 Exploring Waves Discussion Wave vocabulary, then a discussion post on a real-world use of waves
05.03 Wave Behavior Reflection, refraction, diffraction, interference, beats, and the Doppler effect
05.04 Lenses and Mirrors Ray diagrams: locating and describing an image by hand
05.05 Lens and Mirror Equation 1/f = 1/dₒ + 1/dᵢ, solved for any of the three variables
05.06 Lens and Mirror Lab Measuring image position and type across the four object-distance zones
05.07 Snell's Law Index of refraction and n₁sinθ₁ = n₂sinθ₂
05.08 Wave Phenomena Interference, diffraction, dispersion, total internal reflection, polarization
05.08B Telecommunications and Digital Information Analog versus digital signals and how waves carry information
05.08C Engineering Design II Second checkpoint of the three-part engineering design project
05.10 Waves and Optics Exam 80-point exam covering the whole module

What this module is really about

Two everyday examples carry the whole module. First: an ambulance siren sounds different as it passes you, higher pitched coming toward you and lower pitched moving away. Second: light bends when it crosses from air into water, which is why a pencil in a glass looks broken. Both are wave behavior. Sound and light seem unrelated, but they follow the same rules for reflection, refraction, and interference, because both are waves carrying energy from one place to another.

The map ahead

Eleven lessons build in order: SHM sets up periodic motion, wave vocabulary and behavior come next, then optics (lenses, mirrors, Snell's law), then the wave phenomena that tie it together, then the exam. Use the table below as a reference, not a reading assignment.

Final checklist

Tick these off as you go. Saved in this browser.